The Cessna 560 Citation was landing about 6:40 a.m. after a flight from Friedman Memorial Airport in Hailey, Idaho, near the Sun Valley ski resort. It went about 150 yards beyond the runway, smashed through a scaffolding holding airfield equipment and into a commercial storage facility, said Bill Polick, spokesman for the San Diego County Department of Public Works.

One victim was identified as Frank H. Jellinek Jr., 60, chairman emeritus of Fisher Scientific International, a Hampton, N.H., company that provides products and services for labs and clinics. A company statement said Jellinek was appointed chairman emeritus after the 2004 merger of Apogent Technologies and Fisher Scientific. Jellinek was CEO of Apogent before the merger.

Authorities were waiting for dental records to identify the other three victims, two males and a female, said Mike Workman, a San Diego County spokesman.

It was unclear whether the plane ever touched down on the runway before winding up about 30 yards beyond airport property, Polick said.

"There are no skid marks on the runway," he said.

No one on the ground was hurt.

Television footage showed bright orange flames billowing from the aircraft.

The cause of the crash was unknown. Polick said the weather was clear and sunny with only light winds at the time.

Norman Boyd of Escondido said he saw the plane landing as he drove to work near the airport and could tell "the plane was in trouble."

"Its landing gear was up and it was going down really fast," Boyd told The Associated Press in a telephone interview. "It was heading toward the runway and the approaching speed was way beyond what it should be."

The road dipped, obscuring his view of the runway for a moment, and when he saw it again there was "fire and smoke at the far end," he said.

Boyd, who served in the Navy and worked on aircraft, said he observes takeoffs and landings daily on his way to and from work.

The National Transportation Safety Board was sending a team to investigate the accident.

The airport 30 miles north of San Diego was closed for several hours after the crash. It serves private planes, business jets and the commuter airlines America West Express and United Express, both of which operate turboprops out of the facility.

The aircraft was registered to Goship Air LLC of Ketchum, Idaho, authorities said.

According to state incorporation records, Goship Air is owned by Kipp Nelson and Steve Shafran, both of Ketchum. Shafran was appointed this month to the Ketchum City Council and Nelson is an investment banker and a trustee of the U.S. Ski and Snowboard Team Foundation.

Phone calls by the AP to the Sun Valley-area homes of both men were not immediately returned.